Background radiation monitoring via manned helicopter and development of technology for radiation monitoring via unmanned airplane for application of nuclear emergency response technique in the fiscal year 2022 (Contract research)

Futemma, Akira; Sanada, Yukihisa; Sasaki, Miyuki; Kawasaki, Yoshiharu*; Iwai, Takeyuki*; Hiraga, Shogo*; Haginoya, Masashi*; Matsunaga, Yuki*; Akutsu, Yuichiro*; Arai, Yoshinori*; et al.

JAEA-Technology 2023-026, 161 Pages, 2024/03

JAEA-Technology-2023-026.pdf:14.66MB

By the accident at Tokyo Electric Power Company's (TEPCO's) Fukushima Daiichi Nuclear Power Station (FDNPS), caused by tsunami triggered by the 2011 off the Pacific coast of Tohoku Earthquake, a large amount of radioactive material was released into the surrounding environment. After the accident, Airborne Radiation Monitoring (ARM) via manned helicopter has been utilized as a method to quickly and extensively measure radiation distribution surrounding FDNPS. In order to utilize ARM and to promptly provide the results during a nuclear emergency, information on background radiation levels, topographical features, and controlled airspace surrounding nationwide nuclear facilities have been prepared in advance. In the fiscal year 2022, we conducted ARM around the Mihama Nuclear Power Station of Kansai Electric Power Company (KEPCO), the Tsuruga Power Station of Japan Atomic Power Company (JAPC), and the Ikata Power Station of Shikoku Electric Power Company (YONDEN), and prepared information on background radiation doses and controlled airspace. In addition, we have developed an aerial radiation detection system via unmanned airplane, which is expected to be an alternative to ARM, during a nuclear emergency. This report summarizes the results and technical issues identified.

Development of rapid and sensitive radionuclide analysis method by simultaneous analysis of , , and X-rays (Contract research); FY2022 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Japan Chemical Analysis Center*

JAEA-Review 2023-022, 93 Pages, 2023/12

JAEA-Review-2023-022.pdf:4.7MB

The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2022. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2020, this report summarizes the research results of the "Development of rapid and sensitive radionuclide analysis method by simultaneous analysis of , , and X-rays" conducted from FY2020 to FY2022. The present study aims to enable rapid analysis of radionuclides in fuel debris and waste, we have established the latest measurement system, such as the multiple -ray detection methods, and the Spectral Determination Method (hereinafter referred to as "SDM") was developed. In the research in 2022, we developed a code that handles measurement data of LSC, singles Ge, and 2D spectra (multiple ). In addition, to develop an integrated database, spectral data of 40 nuclides were obtained by actual measurements and simulation calculations.

Some considerations on the dependence to numerical schemes of Lagrangian radionuclide transport models for the aquatic environment

Periez, R.*; Brovchenko, I.*; Jung, K. T.*; Kim, K. O.*; Liptak, L.*; Little, A.*; Kobayashi, Takuya; Maderich, V.*; Min, B. I.*; Suh, K. S.*

Journal of Environmental Radioactivity, 261, p.107138_1 - 107138_8, 2023/05

https://doi.org/10.1016/j.jenvrad.2023.107138

Lagrangian models present several advantages over Eulerian models to simulate the transport of radionuclides in the aquatic environment in emergency situations. A radionuclide release is simulated as a number of particles whose trajectories are calculated along time and thus these models do not require a spatial discretization. In this paper we investigate the dependence of a Lagrangian model output with the grid spacing which is used to calculate concentrations from the final distribution of particles, with the number of particles in the simulation and with the interpolation schemes which are required because of the discrete nature of the water circulation data used to feed the model.

Quantitative evaluation of long-term state changes of contaminated reinforced concrete considering the actual environments for rational disposal (Contract research); FY2021 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; The University of Tokyo*

JAEA-Review 2022-057, 98 Pages, 2023/02

JAEA-Review-2022-057.pdf:8.5MB

The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2021. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2020, this report summarizes the research results of the "Quantitative evaluation of long-term state changes of contaminated reinforced concrete considering the actual environments for rational disposal" conducted in FY2021. The present study aims to construct a database for quantitative prediction of contaminated reinforced concrete inside the reactor building. In FY2021, data on deformation and water movement caused by drying and reabsorption of mortar were obtained to evaluate the mesoscale cracking behavior of concrete. A rigidbody spring model was used to develop a program that can consider changes in concrete age and temperature, water, and stress conditions. To evaluate the long-term penetration behavior of radionuclides into the factual matrix, data on sorption …

Development of HCl-free solid phase extraction combined with ICP-MS/MS for rapid assessment of difficult-to-measure radionuclides, 2; Highly sensitive monitoring of Sn in concrete rubble

Do, V. K.; Furuse, Takahiro; Ota, Yuki; Iwahashi, Hiroyuki; Hirosawa, Takashi; Watanabe, Masahisa; Sato, Soichi

Journal of Radioanalytical and Nuclear Chemistry, 331(12), p.5631 - 5640, 2022/12

https://doi.org/10.1007/s10967-022-08612-7

Sn is one of the long-lived fission products that might have been released into the environment after the Fukushima nuclear accident in Japan in 2011. The presence of radionuclides must be monitored for the proper treatment of wastes obtained from decommissioning accident-related nuclear facilities and the surrounding environment. In the work, we propose a reliable method for verifying the presence of Sn in construction materials by combining the HCl-free solid phase extraction on TEVA resin and a selective measurement by inductively coupled plasma tandem mass spectrometry (ICP-MS/MS). The method has been optimized and characterized step by step. More than 95% of chemical recovery was achieved for Sn from typical concrete matrixes. The interference caused by an isobar Te and possible polyatomic interferences from matrixes were effectively suppressed by the developed chemical separation and the tandem MS/MS configuration. The total decontamination factor for the Te interference was of the order of 10. The estimated method detection limit for Sn in concrete as measured at m/z = 160 was 12.1 pg g, which is equivalent to 6.1 mBq g.

Measurement of nuclide production cross sections for proton-induced reactions on Ni and Zr at 0.4, 1.3, 2.2, and 3.0 GeV

Takeshita, Hayato*; Meigo, Shinichiro; Matsuda, Hiroki*; Iwamoto, Hiroki; Nakano, Keita; Watanabe, Yukinobu*; Maekawa, Fujio

Nuclear Instruments and Methods in Physics Research B, 527, p.17 - 27, 2022/09

https://doi.org/10.1016/j.nimb.2022.07.002

To improve accuracy of nuclear design of accelerator driven nuclear transmutation systems and so on, nuclide production cross sections on Ni and Zr were measured for GeV energy protons. The measured results were compared with PHITS calculations, JENDL/HE-2007 and so on.

Current status of Geological disposal by "all-Japan" activities, 6; Post-closure safety assessment (2)

Tachi, Yukio; Saito, Takumi*; Kirishima, Akira*

Nihon Genshiryoku Gakkai-Shi ATOMO, 64(5), p.290 - 295, 2022/05

https://doi.org/10.3327/jaesjb.64.5_290

no abstracts in English

Development of rapid and sensitive radionuclide analysis method by simultaneous analysis of , , and X-rays (Contract research); FY2020 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Japan Chemical Analysis Center*

JAEA-Review 2021-060, 105 Pages, 2022/03

JAEA-Review-2021-060.pdf:4.59MB

The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2020. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2020, this report summarizes the research results of the "Development of rapid and sensitive radionuclide analysis method by simultaneous analysis of , , and X-rays" conducted in FY2020. The present study aims to enable rapid analysis of radionuclides in fuel debris and waste, and develops the measurement system such as multiple -ray detection method. We develop a spectral determination method (SDM method) for integrated analysis by constructing a spectral database for nuclides including -rays and X-rays by measurement using this system and radiation simulation calculation. This method enables simultaneous quantification of multiple nuclides and reduces the chemical separation process.

Developing accelerator mass spectrometry capabilities for anthropogenic radionuclide analysis to extend the set of oceanographic tracers

Hain, K.*; Martschini, M.*; Glce, F.*; Honda, Maki; Lachner, J.*; Kern, M.*; Pitters, J.*; Quinto, F.*; Sakaguchi, Aya*; Steier, P.*; et al.

Frontiers in Marine Science (Internet), 9, p.837515_1 - 837515_17, 2022/03

https://doi.org/10.3389/fmars.2022.837515

Recent major advances in accelerator mass spectrometry (AMS) at the Vienna Environmental Research Accelerator (VERA) regarding detection efficiency and isobar suppression have opened possibilities for the analysis of additional long-lived radionuclides at ultra-low environmental concentrations. These radionuclides, including U, Cs, Tc and Sr, will become important for oceanographic tracer application due to their generally conservative behavior in ocean water. In particular, the isotope ratios U/U and Cs/Cs have proven to be powerful fingerprints for emission source identification as they are not affected by elemental fractionation. Improved detection efficiencies allowed us to analyze all major long-lived actinides, i.e. U, Np, Pu, Am as well as the very rare U, in the same 10 L water samples of an exemplary depth profile from the northwest Pacific Ocean. Especially for Sr analysis, our new approach has already been validated for selected reference materials (e.g. IAEA-A-12) and is ready for application in oceanographic studies. We estimate that a sample volume of only (1-3) L ocean water is sufficient for Sr as well as Cs analysis, respectively.

radioactivedecay; A Python package for radioactive decay calculations

Malins, A.; Lemoine, T.*

Journal of Open Source Software (Internet), 7(71), p.3318_1 - 3318_6, 2022/03

https://doi.org/10.21105/joss.03318